Jaw stretching device

ABSTRACT

A jaw stretching device including a base arm, a lever arm, and a piston arm. A piston channel is formed through the base arm between a connection end and a mouthpiece end. A first mouthpiece is attached to the base arm and a second mouthpiece is attached to the piston arm. The lever arm is connected to the base arm and is capable of rotating relative to the base arm about the connection end. The piston arm includes a length positioned between a pivot end and an attachment end. The length has a curved pattern. The piston arm is positioned in the piston channel and the curved pattern of the length is configured to slide through the piston channel. The lever arm is attached to the piston arm. The piston arm is capable of rotating relative to the lever arm about a pivot end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 60/747,987, filed on May 23, 2006, and is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention generally relates to treatment of the jaw, teeth and face. More specifically, the invention relates to a jaw stretching device.

2. Discussion of Related Art

Medical practitioners have long been asked to help patients regain range and motion in restricted joints. The stiffening or overgrowth of tissue like skin, tendons, joint, scar, ligament, and muscle can limit a patient's joint range-of-motion (ROM). Therapy on and stretching the jaw without a device or appliance is complicated by the joints small size and location.

The lack of good grip positions and limited leverage minimizes control and support for the joint, especially over the small range of jaw motion. Close proximity of the jaw to the brain, ears, nose and mouth, make the joint and area very sensitive to pain and limit therapy in relation to a patient's digestive and respiratory needs. The vulnerability of oral and mucosal tissues around the jaw further complicate stretching, as insertion of hands into the mouth carries more risk for disease transmittal and oral tissue damage. Self-directed exercises are often inadequate as the activated muscles can cause pain, restrict the ability to open, and may not be capable of overcoming the fibrous tissues holding the jaw closed. Physical therapy is thus often limited to massage and teaching the patient stress and pain relief techniques and self-directed exercises for ROM maintenance.

A gripping device, described in U.S. Pat. No. 5,050,586, allows a provider to grab the patient's bottom jaw for manipulation, but is not suitable for unaided use and does not spread the patients jaw. Self-directed and assisted exercises are recommended with reservations, and provide little or no help to patients with restrictive tissue that cannot be lengthened without surgery or anesthetized doctor-assisted manipulation.

Alternatively, doctors and therapists have turned to appliances and medical devices to assist them in improving jaw ROMs. The most basic form of stretching with an appliance is the use of tongue blades, tongue depressors or other flat articles. This method of stretching requires the user to progressively insert tongue blades between the teeth, by pushing or tapping them in. This method of stretching puts pressure on the few teeth bordering the blades, which can loosen, dislodge or break. Furthermore, this method has been shown in medical studies to be ineffective in increasing a patient's ROM.

Over the last generation, manual jaw-stretching devices have been nationally distributed to assist patients, notably a track-press spreader and a pneumatic press device. The track-press spreader, as discussed in U.S. Pat. No. 5,035,420, is a manually driven jaw spreader, where the patient squeezes down on a large device body, pressing two mouthpieces apart to spread the patients jaw. The body is formed by two mirrored halves that join to create a shaped hollow between them. Extending out from the front of the body is a maxillary mouthpiece, which rests against a user's upper teeth during use. Below the upper mouthpiece down the front of the body is a vertical channel that corresponds to the shaped hollow in the body.

Moving backward along the track-press spreader, behind the mouthpiece on top of the body is another channel through the body into the shaped hollow. At the very back, the body hinges in series with pivoting joints to the handle, lever, and carriage—the back of the body connects by hinge to the handle, which connects to the lever, which connects to the carriage. The carriage rests within the shaped hollow of the body, which acts as a curved track for the carriage's motion. Attached to the carriage is the lower mouthpiece, which extends out of the body and moves along the vertical channel. A set screw is threaded through the back of the body to press against the handle. The set screw can be positioned to limit the range of motion of the handle and thus the jaw pieces.

To use the device, the handle is pressed down against the body. This presses the lever, carriage, and mouthpiece down through the hollow in a curved path. As the mouthpiece moves away from the upper mouthpiece, the user's teeth are pressed apart to stretch the jaw. A hand-aid bracket can also be used with the track spreader. This bracket fits around the body and handle, and acts as a surrogate squeezing hand. The user can slide the bracket along the body and handle, and as the bracket slides it pushes the body and handle together to press the lever and spread the mouthpieces.

The structure of the guided track-press device has some drawbacks. The track-press device is large and unwieldy for patients, making it inconvenient to carry in a small bag or with a person. The shaped hollow of the track-press device, which controls the curve of motion for the stretch, is a static part of the body and not easily changed. The track-press device also lacks a structure for providing a consistent sustained stretch to the user. Constant squeezing by the user can hold a stretch but is inconsistent and not capable of providing controlled progressive stretching.

The pneumatic spreader device, described in U.S. Pat. No. 5,562,105, has a handle reservoir within a handle connected by tube to a spreading reservoir within two hinged mouthpiece plates. When a user squeezes the handle, the handle pushes fluid out of the handle reservoir through the tube and into the spreading reservoir. The spreading reservoir fills with fluid and expands to push the two hinged mouthpiece plates apart. When in the user's mouth, the spreading of the two mouthpiece plates works to push the jaw open.

The pneumatic spreader suffers from a weak tube and reservoirs that deform under stress. This deformation inhibits the pneumatic spreader from stretching severely limited patients and will not overcome a user's muscle spasms. The fluid system of the pneumatic spreader is also liable to leak. Furthermore, the shape of the two plates covers a very small area of the teeth and the plates open in an arc opposite to the opening of the jaw.

Both the track-press device and the pneumatic spreader are controlled by the pressure of a hand, which limits stretching to the patient's coordination and strength. Furthermore, neither the track-press nor the pneumatic spreader can sustain a constant opening of the user's jaw.

U.S. Pat. No. 6,361,475 describes another jaw exerciser utilizing an external tube frame and an internal tube slide to press two mouthpieces and the jaw apart. This device is unnecessarily large and the hand-grips are positioned parallel in front of the chin making them hard to squeeze. With the addition of bands, this device works to exercise a patients jaw by providing a constant force that the patient would then bite down against to condition their jaw and head muscles.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention relates generally to a jaw stretching device that includes a base arm having a mouthpiece end and a connection end opposing the mouthpiece end. A piston channel is formed through the base arm between the connection end and the mouthpiece end. A first mouthpiece is attached to the base arm at the mouthpiece end. The first mouthpiece can be shaped to fit a curvature of teeth. A lever arm includes a first and second end, the first end being connected to the connection end of the base arm. The lever arm is capable of rotating relative to the base arm about the connection end. A piston arm includes a pivot end, an attachment end, and a length positioned between the pivot end and the attachment end. The length has a curved pattern. The piston arm is positioned in the piston channel, the curved pattern of the length being configured to slide through the piston channel. The second end of the lever arm is attached to the pivot end of the piston arm. The piston arm is capable of rotating relative to the lever arm about the pivot end. A second mouthpiece is attached to the piston arm at the attachment end. The second mouthpiece can be shaped to fit the curvature of teeth.

In another aspect of the present invention, the present invention relates to a jaw stretching device that includes a base arm having a mouthpiece end and a connection end opposing the mouthpiece end. A piston channel is formed through the base arm between the connection end and the mouthpiece end. A first mouthpiece is attached to the base arm at the mouthpiece end. The first mouthpiece is shaped to fit a curvature of teeth. A lever arm includes a first and second end, the first end being connected to the connection end of the base arm. The lever arm is capable of rotating relative to the base arm about the connection end. A piston arm includes a pivot end, an attachment end, and a length positioned between the pivot end and the attachment end. The piston arm is positioned in the piston channel. The second end of the lever arm is attached to the pivot end of the piston arm. The piston arm is capable of rotating relative to the lever arm about the pivot end. A second mouthpiece is attached to the piston arm at the attachment end. The second mouthpiece is shaped to fit the curvature of teeth. A binding structure arranged to hold the first mouthpiece spaced apart from the second mouthpiece.

These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF DRAWINGS

In order to more fully understand the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered as limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of accompanying drawings.

FIG. 1 is a side view of an embodiment of a jaw stretching device in accordance with the present invention.

FIG. 2 is a perspective view of a jaw stretching device in accordance with another embodiment of the present invention.

FIG. 3 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

FIG. 4 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

FIG. 5 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

FIG. 6 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

FIG. 7 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

FIG. 8 is a side view of a jaw stretching device in accordance with a further embodiment of the present invention.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The present invention generally relates to various embodiments of jaw stretching devices. The jaw stretching device has arms attached together at pivot points, a base arm that hinges to a lever arm, and a piston arm that hinges to the lever arm. On one end of the base arm—opposite the hinged end—a mouthpiece extends out from the base arm. An upward facing maxillary mouthpiece is connected to the base arm mouthpiece. Moving away from the mouthpiece along the base arm toward the pivot end, the next feature is a piston channel connected to, formed in, or contained within the body of the base arm. The pivot end of the base arm includes a hinge, pivot, pin or other structure known by one skilled in the art to provide a pivoting mechanism between the base arm and the lever arm. The lever arm extends outward from the base arm and connects to the piston arm with another pivoting mechanism. The piston arm is arranged to angle and extend from the level arm through the piston channel in the base arm. At the opposite end of the connection point with the lever arm, the piston arm includes a mouthpiece that extends outward and inline with the base arm mouthpiece to fit a user's upper and lower teeth.

In some embodiments a spring is placed between the lever arm and the base arm to force the lever arm and base arm apart. Some embodiments have mouthpieces with releasable clip structures. And some embodiments have a binding structure, which allows those embodiments to maintain a sustained position to stretch the user's jaw. Additionally, some embodiments have a guided piston arm structure. Other features and components can be added to the jaw stretching device to assist a user move and adjust the arm to desired positions to stretch the jaw.

The mouthpieces—such as upper maxillary and lower mandibular mouthpieces—can have a curved bite or occlusal area where the user's teeth would press against the device. From the bite area, a labial rail can be formed to curve along the outside of the curved occlusal area, along where the user's lips are positioned on the mouthpiece. A palatal retention hump can be positioned on the inside of the curved occlusal area, which is positioned to rest behind the user's teeth and inside the mouth by the palate. The various embodiments of the present invention will now be discussed with respect to the accompanying drawings.

In FIG. 1, one exemplary embodiment of a jaw stretching device 1 is illustrated. The jaw stretching device 1 includes a base arm 2, a lever arm 4, and a piston arm 6. The base arm 2 is attached to the lever arm 4 at a pivot end 5. The pivot end 5 can include a hinge, pin, pivot, plastic living hinge or other structure known by one skilled in the art to provide a pivoting connection between the base arm 2 and the lever arm 4. At the opposing side of the base arm 2 a mouthpiece 8 a extends outward from the base arm 2. The mouthpiece 8 a includes an occlusal area 10 to fit a user's set of teeth, as illustrated in FIG. 2. The lever arm 4 is arranged to pivot relative to occlusal area 10 of the mouthpiece 8 a.

In this exemplary embodiment, the pivot end 5 between the lever arm and base arm can be a pivot pin 12 fit in a pivot socket 13. The pivot socket 13 is formed through the base arm 2 and the lever arm 4. The pivot pin 12 is inserted through and fix in the pivot socket 13 to provide a pivoting connection between the base arm 2 and the lever arm 4. The lever arm 4 can rotate about an axis in a motion towards or away from the base arm 2, i.e. relative to the base arm 2.

The lever arm 4 is attached to the piston arm 6 at a connection point 14. The connection point 14 includes a pivoting mechanism, such as a hinge, pin, pivot, plastic living hinge or other structure known by one skilled in the art to provide a pivoting connection between the lever arm 4 and the piston arm 6. In this exemplary embodiment, the connection end 14 between the lever arm 4 and piston arm 6 can be a pivot pin 15 press fit or formed as part of the piston arm 6. A pivot socket 16 can be formed in or through the lever arm 4. The pivot pin 15 fits into the pivot socket 16 and is arranged to provide a pivoting connection between the lever arm 4 and the piston arm 6.

A piston channel 17 is formed, cut, or molded in the base arm 2 and shaped to fit and allow the piston arm 6 to slide along a guiding edge and between side edges of the piston arm 6. The guiding edge is the edge of the piston channel 17 that parallel to and nearest to the base arm's pivot end. The piston channel 17 can also be open on one side of the base arm to form a C-channel cut in the base arm 2. The piston arm 6 hinges down to fit through the piston channel 17 of the base arm 2 against the guiding edge.

Another mouthpiece 18 a is connected to a side opposing the connection end of the piston arm 6 and is arranged to extend outward from the piston arm 6 and inline with the mouthpiece 8 a of the base arm 2. The mouthpiece 18 a extends out from the piston arm 6 at a predetermined angle. The mouthpieces 8 a, 18 a are arranged to fit the upper and lower teeth of a user, for example, a mandibular mouthpiece and a maxillary mouthpiece. The mouthpiece 18 a of the piston arm 6 is angled to position the mandibular mouthpiece inversely to the maxillary mouthpiece. The mouthpiece 18 a of the piston arm 6 can be similar to the mouthpiece 8 a of the base arm 2 or different depending on the needs of the application and/or the user. For example, the mouthpiece 18 a of the piston arm 6 can also include an occlusal area to fit a user's set of teeth as discussed above. The mouthpieces can also be made of a flexible material to bend or provide constant pressure against a user's teeth during use. The mouthpieces can also have different widths and lengths, or extend out from the device at different distances to accommodate a user with variation in their bite, as discussed below. The mouthpieces 8 a, 18 a in this embodiment are directly attached to the base arm 2 and piston arm 6, respectively.

The jaw stretching device 1 should be sized to provide a maximum distance of about 40mm to about 65mm between the mouthpieces for humans. This would approximately necessitate a human device with a piston arm of between about 45 mm and about 70 mm, taking into account the hinge and thickness of the mouthpieces. For patients with a minimal opening, the thickness of the mouthpieces through the occlusal area will be between about 1 mm and about 5 mm, with a palatal retention rail of about 0 mm to about 10 mm. The lever arm can be between about 40 mm to about 200 mm, with a base arm including additional length for the lever edge, the channel, and the mouthpiece. The piston arm can have a mouthpiece with dimensions corresponding to the size of the base arm and intended user. Larger or smaller dimensions can be designed for other animals, like horses or dogs or in cases of meeting needs of exceptionally large or small human structures.

The jaw stretching device 1 functions by the pressing or squeezing the lever arm towards the base arm. To use the device, a user inserts the maxillary and mandibular mouthpieces into their mouth, the respective bite areas against their teeth. The user or assistant grasps the device around the lever and base arms; e.g. with their thumb under the base arm and their fingers wrapping around the base and lever arm. The user squeezes the lever arm toward the base arm, which pushes the piston arm through the piston channel and moves the mandibular mouthpiece away from the maxillary mouthpiece. This motion pushes the users' teeth apart to stretch the tissues of the jaw and face.

As shown in FIG. 2, a spring 19 can be placed between the lever arm 4 and base arm 2 to force the lever arm 4 and base arm 2 away from each other to bring the mouthpieces 8, 18 next to each other when the user releases the device. This spring mechanism can hold the lever arm 4 in a position spaced from the base arm 2 when no force is compressing the base arm 2 and lever arm 4 together. The spring 19 also provides some resistance to the squeezing of the device for fluid motion and as a damper on the velocity and force applied to and by the user. The spring 19 is not required for the device to function, but acts to support the device and would provide a counter pressure to the squeezing of the base and lever arm. The strength of the spring can be predetermined to reduce the overall force pushing the mouthpieces apart as a safety precaution to prevent the application of excessive force on the user's jaw.

The spring 19 can be a torsion spring, as illustrated in FIG. 2, or another type of spring mechanism known by one skilled in the art to force the lever arm and base arm apart from each other, for example a compression spring, plastic spring bar, or the like.

The embodiment of the jaw stretching device illustrated in FIG. 2 also includes a guide mechanism to guide the movement of the piston arm 6 through the base arm 2. A base opening 20 is formed, cut, or molded into the base arm 2 to provide a space for the piston arm 6 to move through the base arm 2. The guide mechanism includes a travel pin 22, piston guides 24, and a piston channel 26. The travel pin 22 is attached to one or both sides of the base arm 2 and arranged to guide the piston arm 6 through the base opening 20. At least one side of the piston arm 6 includes piston guides 24 and a piston channel 26. The piston guides and channel 24, 26 are placed or formed on the piston arm 6 to be associated with the travel pin 22. The travel pin 22 slides in the piston channel 26 and between the piston guides 24 to direct the movement of the piston arm 6.

The mouthpieces 8, 18 can be fixed to the device or capable of being interchanged. The mouthpieces 8, 18 are detachable as illustrated in FIG. 2. In this embodiment, each mouthpiece includes a mouthpiece clip 28 and a mouthpiece socket 29. The mouthpiece clip 28 is configured to clip into the mouthpiece socket 29 when the mouthpiece is inserted into the device. The mouthpiece clip 28 includes clip release sides 32 and a clip support 30 arranged between the clip release sides 32. The clip release sides 32 are configured to be inserted into a clip entrance 36 in front of the mouthpiece socket 29 and snap into place to hold the mouthpiece in the mouthpiece socket. The mouthpiece clip 28 snaps into the mouthpiece socket 29 when the clip release sides 32 latch with a release opening 38 in the sides of the mouthpiece socket 29. The mouthpiece clip 28 is released from the mouthpiece socket when the clip release sides 32 are pushed in through the release opening 38 and the mouthpiece clip 28 is slid out from the mouthpiece socket 29.

The embodiment illustrated in FIG. 2 also includes a binding structure. The binding structure includes notches 40 formed, cut, or molded along a surface of the piston arm 6. The notches 40 are aligned with an edge of the base opening 20 to provide incremental movement. The piston arm 6 slides through the base opening with a friction fit along the edge with the notches 40, by sliding past one notch at a time.

Another embodiment of a jaw stretching device is illustrated in FIG. 3 having a limit structure. The limit structure includes notches 40 in the piston arm 6 and a limit clip 42. The limit clip 42 can be placed along the piston arm 6 at a desired maximum opening distance. When the lever arm 4 and base arm 2 are pushed together, the mouthpiece 8 and a mouthpiece 43 are spread apart until the limit clip 42 rests against the base arm 2 and prevents the piston arm 6 from sliding further through the base arm 2. In this manner, the position of the limit clip 42 on the piston arm 6 corresponds directly to the opening distance of the mouthpieces 8, 43.

FIG. 3 also illustrates a jaw stretching device with mouthpieces of different lengths. The mouthpiece 43 is shortened and connected to the side opposing the connection end of the piston arm 6 and is arranged to extend outward from the piston arm 6. The shortened mouthpiece 43 is positioned inverted to the mouthpiece 8. The components of the mouthpieces 43, 8 are shifted along their horizontal axis in relation to their difference in length. This shift allows the maxillary and mandibular teeth of a user with an underbite to align with the occlusal areas of the mouthpieces 8, 43. The mouthpieces could also be reversed with the shortened mouthpiece 43 being connected to the base arm 2 and the mouthpiece 8 connected to the piston arm 6 for users with overbites. Different length mouthpieces with a mouthpiece clip 28 can thus be changed by a user to best accommodate their individual bite.

FIG. 4 illustrates a further embodiment of a jaw stretching device 1. The device includes a guide mechanism having a pin channel 44 and a shaped travel pin 46. The pin channel 44 is formed, cut, or molded in the lever arm 4 and the pivot pin is inserted into the pin channel 44. As the piston arm 6 slides through the base arm 2, the pivot pin 15 can slide back and forth through the pin channel 44 with movement A to accommodate any variations in the movement of the piston arm 6 through the base arm 2. The shaped travel pin 46 is attached to at least one side of the base arm 2. A shaped travel pin 46 can be attached to both sides of the base arm 2. The shaped travel pin 46 has an elongated shape to fit in the channel 26 and between the piston guides 24, which forces the piston arm 6 to rotate according to the curvature in the piston arm 6 by moving the pivot pin 15 in the pin channel 44.

For example, one path of motion of the jaw stretching device as the lever and base arms are squeezed together can be curved based on the curvature in the piston arm 6 and may correspond with the curves in motion of human jaw. As the lever arm is pressed, the piston arm moves down along the base arm 2. The closer the arms are pushed together, the relative increase in angle between the piston arm 6 and lever arm 4 and decrease of the angle between the piston arm 6 and base arm 2 works to accelerate the curve of the path, quickening the curve as the piston arm descends.

The shape of the present invention's path of motion is determined by a number of variables, notably the length of the lever arm, the difference in length between the lever arm and the base arm from hinge to lever edge, and the shape of the piston arm. The path is thus formed in a complex relationship capable of providing wide variation. An example of these shapes would arise from a change in the distance on the base arm to the lever edge, which would shift the shape and acceleration of the curve in the path of motion. Or alternatively, a shaped piston arm could straighten or ladder the path of motion, or add other desired movements both vertical and lateral. For instance, a path can include a smaller curve generated from a wider difference between the lever arm and the base arm hinge-to-channel lengths. Another path can include a straighter path that could be created from a curved piston arm. A further path can include steps and a non-uniform curve.

As shown in FIG. 5, another embodiment of a jaw stretching device 1 includes a binding structure having a compression band 48 and a limit screw 50. The embodiments with binding structures work to allow the user to move the device to a predetermined distance between the mouthpieces, which can be held by the device without a sustained force by the user. In this embodiment, the device has base arm 2, lever arm 4, and piston arm 6 connected in hinged sequence, with the piston arm 6 located through the piston channel 17 of the base arm 2. A mouthpiece 8 is attached at the non-hinged end of the base arm 2 and another mouthpiece 18 is attached at the piston arm 6. This embodiment of a binding structure includes a compression mechanism and a control structure. The compression mechanism is a compression band 48, such as an elastic or rubber band wrapped around notches 52, 54 in the base arm 2 and the lever arm 4.

The control structure is a limit screw 50 or bolt through the base arm 2, which is arranged to press against the lever arm 4. This screw can be placed anywhere along the base arm 2 or lever arm 4. In this embodiment, the limit screw is positioned at the pivot end 5, near the pivot pin 12, and is a set screw including a threaded rod 56 and a knob 58. The limit screw 50 is threaded through a threaded aperture 59 near the pivot end 5. The limit screw 50 can limit the range of the device, which can be turned to change the distance between the base arm 2 and the lever arm 4. When the end of the limit screw 50 is closer to the lever arm 4, the limit screw will quickly hit the lever arm 4 and stop the lever arm 4 from lowering. When the end of the limit screw 48 is further from the lever arm 4, it will allow a larger range of motion.

In this embodiment, the compression mechanism has a predetermined force sufficient to press the two mouthpieces apart while between the teeth of a user. The pressure of the band pushes the mouthpieces apart to stretch the users jaw. The distance of this stretch is determined by the control structure, such as the limit screw 50. The limit screw can be threaded to a predetermined position, which limits the distance the piston arm can push the mouthpieces apart to act as a control structure on the movement of the device. This binding structure with a compression mechanism and control structure allows the device to retain and hold a user's opening at a controlled distance for a sustained stretch. To increase or decrease the opening and the stretch, the user moves the control structure accordingly against or with the force of the compression mechanism. Furthermore, by removing or fully retracting the limit screw or other control structure, the device can act as a dynamic splint, providing a constant force on the user's teeth and jaw.

FIGS. 6, 7, and 8 further illustrate components of embodiments with binding structures having similar structures to those discussed above with the base arm, lever arm, piston arm, and mouthpieces. The embodiment in FIG. 6 uses a control screw 60 as a binding structure, a control screw opening 62 in the lever arm 4, and a threaded aperture 64 through the base arm 2. The control screw 60 rests within the control screw opening 62 on the lever arm 4. The control screw 60 has a knob 66 that is larger than the control screw opening 62, and extends down into the threaded aperture 64 on the base arm 2.

The knob 66 of the control screw 60 presses against the lever arm 4, with the base and lever arms at a distance determined by the length of the control screw 60 and depth of threading 68 into the threaded aperture 64. By adjusting the control screw 60 through the threaded aperture 64, the top of the control screw 60 pushes down on the lever arm 4 to push the mouthpieces 8, 18 apart. As the lever arm 4 angles downwards toward the base arm 2, the control screw opening 62 is shaped to allow the lever arm 4 to rotate in relation to the axis of the control screw 60 and threaded aperture 64.

The control screw 60 can be made as a thumbscrew or of any shape to allow for easy turning and manipulation by the user, like threaded knobs, wing bolts or any other type as known to one skilled in the art. In other alternative embodiments, binding structures can include a ratchet mechanism between the lever and base arm instead of a threading bolt.

FIG. 7 illustrates a jaw stretching device 1 including cushioning 70, a sliding distance marker 72, and a binding structure. The cushioning 70 is attached to the base arm 2 and the lever arm 4 and arranged to provide a soft gripping surface. The cushioning can be applied to the entire or part of the outer surfaces of the base arm 2 and lever arm 4 using an adhesive or glue. The cushioning 70 can also be coated on the base arm 2 and lever arm 4. The cushioning 70 can be made of a soft plastic, foam, or other material known by one skilled in the art to cushion a gripping surface.

The distance marker 72 is slidably attached to the piston arm 6. The distance marker 72 moves along the piston arm 6 when the piston arm 6 travels through the base arm 2. When the distance marker 72 collides with the base arm 2, the distance marker 72 slides along the piston arm 6 to mark the distance through which the piston arm 6 traveled through the base arm 2. The user can view the distance marker 72 to measure the travel distance between the mouthpieces 8, 18 after using the jaw stretching device. The notches 40 or other marks can indicate a numerical length for the measured travel.

The binding structure includes notches 40 formed, cut, or molded along a surface of the piston arm 6, and a ratchet 74. The notches 40 are aligned with an edge of the base opening 20 and the ratchet 74 is aligned to engage the notches 40. The ratchet 74 is attached to the base arm 2 with a torsion pin 76 that is configured to rotate the ratchet 74 toward and away from the notches 40. One end of the ratchet 74 includes a release 78 that extends out from the base arm 2 to provide a lever mechanism to release the ratchet 74 from engagement with the notches 40. An opposite end of the ratchet includes a clip 80 that is configured to engage a notch on the set of notches 40. The ratchet 74 can incrementally move along the notches 40 by sliding past one notch at a time. When the base arm 2 and lever arm 4 are pushed together, the mouthpieces 8, 18 are spread apart while the ratchet 74 moves along the piston arm 6. The ratchet 74 holds the distance between the mouthpieces 8, 18 until the release 78 is pressed to disengage the ratchet 74 from the notches 40.

FIG. 8 illustrates another embodiment of the device with sockets 82 or holes through the piston arm 6. One or more holes could be set through the side of the channel in the base arm 2, and a setting device, clip or pin would create a binding structure. This embodiment allows the user to place a pin 84 through the base arm 2 and piston arm 6. The pin 84 can either enter into the piston arm 6 or behind the piston arm 6. By connecting with the piston arm 6 in a socket 82, the pin 84 can hold the arms in place and thus hold the distance between the mouthpieces 8, 18. This hold would allow a user to sustain a distance and stretch with the device. Alternatively, if the pin 84 rested behind the piston arm 6, the pin 84 can act as a substitute edge. This substitute edge would change the shape of the path of motion, based on the new relationship of distance between the lever arm length and base arm with the substitute edge.

The various embodiments can include a shaped piston arm that is curved or straight. A shaped piston arm acts to change the shape of the path of motion in a predetermined alternative path. A curved arm can act to straighten the curve in the path. The device is capable of employing any shaped piston arm that is mechanically functional within a hinged device through the channel to create a corresponding path predetermined to move the mouthpieces apart in a desired way. Various shaped piston arms could be used interchangeably on a single device with a releasable hinge and channel.

Other embodiments of the device can utilize a piston arm guide that would allow for additional paths along multiple axes. The piston arm can have a hinge allowing for lateral and vertical motion. The piston arm guide includes a shaped track cut out of the arm, in the shape of an ellipse and a guide pin attached to and extending from the base arm or press edge. With the piston arm guide, the guide pin slides along the shaped track in the piston arm to correspondingly move the arms and mouthpieces in predetermined paths. The external edge of the ellipse is cut from the arm, and the inner edge is created by holding an inner edge piece in place by a track fastener. The fastener can include a bar across the arm and attached to both the arm and the inner edge piece. This shaped track would provide lateral motion between the mouthpieces, in addition to the vertical motion. The shaped track and its components can be part of a track insert that could be removed and replaced within the piston arm.

Alternatively, an embodiment with a carriage and track in the cavity of the base arm could also be made with the other binding structures described above. One alternative binding structure would include the set screw being inserted through a hole in the back of the base arm, into a threaded bore in the back of the lever arm. By threading the set screw, the lever arm would move to adjust the piston arm and the lower mouthpiece.

In the various embodiments, the parts can be made of hard plastic like ABS, PE, nylon, acrylic, polypropylene or urethane plastics, with the mouthpieces being of a material suitable for oral use. However these parts can consist of any other material that is sufficiently stiff and safe such as plastic, laminated fibrous materials, other plasticized materials, wood, metal, or any other known to one skilled in the art. The springs can be made of metal or plastic, as coils, torsion springs, flat springs, wire, stamped, strip and flat forms, or any other kind as known to one skilled in the art with predetermined force for its embodiment. The compression mechanism can be made of any material or structure that can provide a compressive force, including rubber, elastic fabric, a plastic ratchet loop, or any other material known to one skilled in the art with predetermined force sufficient for its embodiment; including the use of a compression spring for the spring.

Alternative embodiments of the stretching device include variations of the mouthpiece shape, occlusal padding like wax and foam, and mouthpiece structures that could be releasable, interchangeable, or moveable. In alternative embodiments the arms could be ergonomically shaped for improved comfort and aesthetic appeal; they could be wrapped or enclosed by a body or case; they could be designed for right- or left-handed versions; they could have measuring or unlabeled distance markers on the piston arm; they could be of various lengths and widths; a sliding distance marker could be around the piston arm; or the base arm channel could be closed, could extend out from the base arm, or be outside the base arm. The mouthpiece bars on the base and piston arms could be alternatively angled on any axis to change where the user would press them together.

Furthermore, the clip structure, the binding structure and many of the alternatives could also be applied as improvements to a device with a carriage and track system, like the track-press spreader. 

1. A jaw stretching device, comprising: a base arm including a mouthpiece end and a connection end opposing the mouthpiece end, a piston channel being formed through the base arm between the connection end and the mouthpiece end; a first mouthpiece attached to the base arm at the mouthpiece end, the first mouthpiece being shaped to fit a curvature of teeth; a lever arm including a first and second end, the first end being connected to the connection end of the base arm, the lever arm being capable of rotating relative to the base arm about the connection end; a piston arm including a pivot end, an attachment end, and a length positioned between the pivot end and the attachment end, the length having a curved pattern, the piston arm being positioned in the piston channel, the curved pattern of the length being configured to slide through the piston channel, the second end of the lever arm being attached to the pivot end of the piston arm, the piston arm being capable of rotating relative to the lever arm about the pivot end; and a second mouthpiece attached to the piston arm at the attachment end, the second mouthpiece being shaped to fit the curvature of teeth.
 2. The device of claim 1, further comprising a spring arranged to force the base arm and lever arm apart.
 3. The device of claim 1, further comprising a limit structure, the limit structure being arranged to limit movement of the piston arm relative to the base arm.
 4. The device of claim 1, further comprising a guide mechanism, the guide mechanism being designed to direct motion of the piston arm along a predetermined path.
 5. The device of claim 4, wherein the guide mechanism includes guides formed on at least one side of the piston arm and a travel pin disposed on the base arm, the travel pin being arranged to slide in the guide as the piston arm slides through the piston channel.
 6. The device of claim 5, wherein the second end of the lever arm is attached to the pivot end of the piston arm with a pivot pin, the lever arm further including a pin channel, the pivot pin being positioned in the pin channel and being capable of sliding in the pin channel as the travel pin slides through the channel on the piston arm.
 7. The device of claim 1, further comprising a cushion disposed along at least one of the lever arm and the base arm to provide a grip for a user.
 8. The device of claim 1, further comprising a sliding marker disposed on the piston arm, the sliding marker being configured to mark a position on the piston arm relative to a distance between the first mouthpiece and the second mouthpiece.
 9. A jaw stretching device, comprising: a base arm including a mouthpiece end and a connection end opposing the mouthpiece end, a piston channel being formed through the base arm between the connection end and the mouthpiece end; a lever arm including a first and second end, the first end being connected to the connection end of the base arm, the lever arm being capable of rotating relative to the base arm about the connection end; a piston arm including a pivot end, an attachment end, and a length positioned between the pivot end and the attachment end, the piston arm being positioned in the piston channel, the second end of the lever arm being attached to the pivot end of the piston arm, the piston arm being capable of rotating relative to the lever arm about the pivot end; and a first mouthpiece is attached at the connection end of the base arm and a second mouth piece is attached at the attachment end of the piston arm with clip sockets, one clip socket being placed between the first mouthpiece and the base arm, and another clip socket being placed between the second mouthpiece and the piston arm, the first and second mouthpieces being capable of being removed from the clip sockets.
 10. The device of claim 9, wherein the clip sockets include side openings and the first and second mouthpieces include clips, the clips being arranged to engage the side openings of the clip sockets when one of the first and second mouthpieces is inserted into the clip socket.
 11. The device of claim 9, wherein the first mouthpiece has a different length than the second mouthpiece, the mouthpieces being attached to accommodate a user with variation in their bite.
 12. A jaw stretching device, comprising: a base arm including a mouthpiece end and a connection end opposing the mouthpiece end, a piston channel being formed through the base arm between the connection end and the mouthpiece end; a first mouthpiece attached to the base arm at the mouthpiece end, the first mouthpiece being shaped to fit a curvature of teeth; a lever arm including a first and second end, the first end being connected to the connection end of the base arm, the lever arm being capable of rotating relative to the base arm about the connection end; a piston arm including a pivot end, an attachment end, and a length positioned between the pivot end and the attachment end, the piston arm being positioned in the piston channel, the second end of the lever arm being attached to the pivot end of the piston arm, the piston arm being capable of rotating relative to the lever arm about the pivot end; a second mouthpiece attached to the piston arm at the attachment end, the second mouthpiece being shaped to fit the curvature of teeth; and a binding structure arranged to hold the first mouthpiece spaced apart from the second mouthpiece.
 13. The device of claim 12, wherein the binding structure includes a limit screw attached between the base arm and the lever arm, the limit screw being arranged to abut against one of the base arm and lever arm to adjust the space between the first and second mouthpieces.
 14. The device of claim 13, further comprising a compression band attached to the lever arm and the base arm, the compression band being arranged to force the lever arm and base arm together.
 15. The device of claim 12, wherein the binding structure includes a control screw attached between the base arm and the lever arm, the control screw being arranged to adjust the space between the first and second mouthpieces when the control screw is rotated in one direction to force the base arm and lever arm apart and when the control screw is rotated in another direction to force the base arm and lever arm together.
 16. The device of claim 12, wherein the binding structure includes a set of notches formed into the piston arm, and further comprising a limit clip capable of being attached to the piston arm at a notch in the set of notches, the limit clip being attached in a position to limit movement of the piston arm through the base arm, the position corresponding to the space between the first and second mouthpieces.
 17. The device of claim 12, wherein the binding structure includes a ratchet system placed between the piston arm and the base arm to adjust the space between the first and second mouthpieces.
 18. The device of claim 17, wherein the ratchet system includes a set of notches formed in the piston arm and a ratchet clip attached to the base arm, the ratchet clip being arranged to insert into a notch of the set of notches and move to another notch in the set of notches in one direction along the piston arm to hold the space between the first and second mouthpieces.
 19. The device of claim 12, wherein the binding structure includes a spring arranged to force the base arm and lever arm apart.
 20. The device of claim 12, wherein the binding structure includes a set of sockets formed in the piston arm and a set pin, the set pin being selectively placed in one of the sockets to hold the space between the first and second mouthpieces. 